This invention relates to a module for a modular conveyor belt which has a retainer for retaining a hinge rod in the module and which enables a hinge rod to be retracted from the module without damaging the retainer.
A modular conveyor belt is a conveyor belt formed from a plurality of units (referred to as modules) pivotably connected to each other end to end in series. Modular conveyor belts are popular in the product handling industry because the length of such conveyor belts can be readily adjusted by varying the number of modules making up the conveyor belts. Furthermore, a modular conveyor belt is easy to repair when worn or damaged by simply replacing any worn or damaged modules without it being necessary to replace the entire conveyor belt.
The modules forming a modular conveyor belt are pivotably connected in series by elongated hinge rods which pass through aligned bores formed in the modules. Various means have been employed to prevent the hinge rods from inadvertently becoming detached from the modules during operation or handling of a modular conveyor belt. One commonly used system for retaining a hinge rod employs a finger-like retainer having a fixed end secured to some portion of the module and a free end. The retainer can flex about the fixed end between a position in which the free end extends across the path of axial movement of a hinge rod disposed in the module to prevent retraction of the hinge rod from the module, and a position in which the free end of the retainer is disposed out of the path of axial movement of the hinge rod to permit the hinge rod to be retracted from the module.
When a modular conveyor belt equipped with such a retainer is being serviced and a technician desires to remove a hinge rod from the conveyor belt, it is common for the technician to move the retainer between the two positions by exerting a prying force on the retainer using a rigid member such as a screwdriver. This method of bending the retainer may not cause a problem if the prying force is exerted near the free end of the retainer, but if the prying force is applied near the fixed end or near the midportion of the retainer, the retainer can easily be subjected to stresses which exceed its design stress. As a result, the retainer may undergo plastic deformation of an extent such that it cannot return to a position in which it prevents retraction of a hinge rod, and it may even undergo structural failure, i.e., it may break. In either case, the retainer can no longer retain a hinge rod in the conveyor belt.